> Higher latitudes have colder climates.
Not reliably, not continually, and much less often when you dump enough energy into the atmosphere to disrupt major wind patterns.
British Columbia hitting 121°F/49.6°C at 50°N latitude would sort of suggest your generalization doesn't hold true anymore.
Yes, polar regions are reliably colder than equatorial regions. Lytton, BC hit the temperature you cite for one day on Tuesday, June 29, 2021. That's a sign of warming, and we should expect more warm days than in the past at any given lattitude. But it is not evidence against the general case that polar regions have colder climates than equatorial regions.
Here's a citation demonstrating that over the last 95 million years if you need one: https://www.pnas.org/doi/10.1073/pnas.2111332119
One more just for fun: https://journals.ametsoc.org/view/journals/clim/12/4/1520-04...